Marketable securities (Tables)

6 Months Ended

Jun. 30, 2025

Marketable securities

Schedule of Marketable Securities

			Cost or
			amortized		Unrealized
	Market value		cost		gain, net
	(In millions)
December 31, 2024:
Current assets	$	1.9	$	1.9	$	—
Noncurrent assets	$	5.7	$	5.7	$	—
June 30, 2025:
Current assets	$	2.4	$	2.4	$	—
Noncurrent assets	$	4.7	$	4.5	$	.2